Armature control system

ABSTRACT

An armature control system including coil means for controlling positioning of a movable armature. Electrical resistance means is provided which has transverse portions in heat exchange relationship with each other and flexible for movement toward and away from one another to adjust the heat exchange relationship, the electrical resistance of the portions being temperature responsive so current flow therethrough is responsive to the temperature thereof. Adjustment means is provided for moving the portions toward and away from one another to adjust the proximity thereof and alter mutual heat transfer therebetween so the electrical current passing through the resistance means is correspondingly adjusted. Circuit means connects the resistance means with the coil means so the adjustment means may be adjusted to adjust the spacing between the transverse portions to alter the heat exchange relationship therebetween and adjust the current flow through the coil means to thereby adjust the electromagnetic force on the armature to effect movement thereof.

United States Patent [451 May 23, 1972 McIntosh [54] ARMATURE CONROL SYSTEM 72 Inventor: Harold A. McIntosh, South Pasadena,

Calif.

[73] Assignee: Robertshaw Controls Company,

Richmond, Va.

[22] Filed: Mar. 10, 1971 21 App]. No.: 122,728

Related US. Application Data [62] Division of Ser. No. 805,138, Mar. 7, 1969, Pat. No.

[52] U.S.C1. ..317/132,317/155.5,338/31 [51] lnt.Cl. ..H0lh 47/26 [58] Field ofSearch ..317/132, 155.5; 338/31 [56] References Cited UNITED STATES PATENTS 2,199,910 5/1940 Cunningham ..3l7/155.5 2,307,077 1/1943 Reagan ..3l7/l55.5 2,340,004 1/1944 McGrath... .....317/155.5 2,758,294 8/1956 Duncan ..323/75 N Primary Examineh-L. T. Hix Attorney-Fulwider, Patton, Rieber, Lee & Utecht [57] ABSTRACT An armature control system including coil means for controlling positioning of a movable armature. Electrical resistance means is provided which has transverse portions in heat exchange relationship with each other and flexible for movement toward and away from one another to adjust the heat exchange relationship, the electrical resistance of the portions being temperature responsive so current flow therethrough is responsive to the temperature thereof. Adjustment means is provided for moving the portions toward and away from one another to adjust the proximity thereof and alter mutual heat transfer therebetween so the electrical current passing through the resistance means is correspondingly adjusted. Circuit means connects the resistance means with the coil means so the adjustment means may be adjusted to adjust the spacing between the transverse portions to alter the heat exchange relationship therebetween and adjust the current flow through the coil means to thereby adjust the electromagnetic force on the armature to effect movement thereof.

10 Claims, 1 Drawing Figure Patented May 23, 1972 3,665,258

INVENTOR. H0204 A. Md/NTOSH ARMATURE CONROL SYSTEM CROSS REFERENCE TO RELATED APPLICATIONS This application is a divisional application of U.S. Ser. No. 805,138 filed Mar. 7, 1969 now U.S. Pat. No. 3,577,066.

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrical control system for controlling the position of an armature such as a heating system operator in response to adjustment of an adjustment means such as a temperature sensor.

2. Description of the Prior Art It has been common practice to provide conventional potentiometers for controlling movement of an armature. However, conventional potentiometers suffer the shortcoming that the resistance of the resistors included therein may not be uniform throughout their length thereby providing for erratic responses when the wiper position is adjusted. Further, movement of the wipers of conventional potentiometers frequently causes sparking between such wipers and the potentiometer resistors thereby making such devices unacceptable for use in an explosive environment SUMMARY OF THE INVENTION The present invention is characterized by a movable armature having coil means disposed adjacent thereto and connected with electrical resistance means in the form of trans verse portions disposed in heat exchange relationship and flexible for movement toward and away from one another to adjust the heat exchange relationship between such transverse portions to thereby adjust the overall resistance of such resistance means and adjust the current to the coil means.

An object of the present invention is to provide an armature control system of the type described which incorporates a divided circuit having current to opposite sides of such circuit altered in inverse relationship in response to adjustment of the resistance means.

Another object of the present invention is to provide an armature control system of the type described which provides for control of an operator in response to variances in a selected parameter.

These and other objects and the advantages of the present invention will become apparent from a consideration of the following detailed description when taken in conjunction with the accompanying drawing.

, trical circuit depicting an armature control system embodying the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT The armature control system of present invention includes, generally, a movable armature 11 having a pair of coils l3 and 15 telescopically received over the opposite ends thereof and connected with an electrical resistor 19 by means of an electrical circuit 21. The resistors 17 and 19 are in the form of a helical coil resistor having a plurality of respective transversely extending coils and 27 which are disposed in heat exchange relationship with one another and are flexible for movement toward and away from one another. A thermostatic blade 29 has its free end connected with the common ends of the resistors l7 and 19 whereby heating of such blade will flex the free end thereof upwardly to the broken line position to collapse the resistor 17 to move the coil 25 into closer spaced relationship and to expand the resistor 19 to move the coils 27 therein into spacings of a greater distance. Such adjustment of the resistor 17 increases the rate of mutual heat exchange between the coils 25 thereby increasing the temperature of the resistor 17 to accordingly decrease the current through the coil 15. Correspondingly, the expansion of the resistor 19 decreases the rate of heat exchange between the coils 27 to enable such resistor to cool thereby lowering the resistance thereof and increasing the rate of current flow through the coil 13 to increase the electro-magnetic force thereof to draw the armature 11 to the lefi and effect adjustment thereof in accordance with the temperature sensed by the blade 29.

As noted hereinabove, the armature control system of present invention may conveniently be utilized for controlling the rate of heat delivered to an environment in response to the temperature sensed in such environment.

In the preferred embodiment the resistors 17 and 19 are in the form of helical coils wherein the coils of wire are flexible and disposed in heat exchange relationship with one another. The rate of mutual heat exchange is altered by elongating or shortening the helix to thereby adjust the distance between the individual coils. Other resistor structures in which portions thereof are formed for location in adjacent heat exchange relationship will suggest themselves to those skilled in the art. All such variations are within the scope of the present invention, it being important only that flexing or deformation of the resistors 17 and 19 results in alteration of the heat exchange relationship of adjacent portions 17 and 19 to thereby effect the electrical characteristics of such adjacent portions.

The resistors 17 and 19 are made of a material possessing the property of experiencing a relatively high change in resistance for a relatively small change in temperature. That is, the material is characterized by a high co-efficient of temperature resistance. Pure nickel exhibits this characteristic as do the materials sold under the trade name Balco" and Hy- Tempco.

The resistors 17 and 19 are preferably formed from one continuous coil and have the free end of the thermostatic blade 29 connected to a node 31 formed at their proximate ends. The top end of the resistor 17 is connected with one end of the coil 13 by means of a lead 35 and the opposite end of such coil is connected with a circuit node 37 by means of a lead 39. The node 37 is also connected with one end of the coil 15 by means of a lead 41 and the opposite end of such coil is connected with the lower end of the resistor 19 by means of a lead 43. The node 31 formed between the resistors 17 and 19 is connected with a positive lead 47 by means of a lead 49 and the node 37 is connected with a negative lead 51.

The armature 11 is incorporated in a switch operator, generally designated 57, which switch operator 57 is in the form of a pendulum having an electrically conductive vertical stem 61 which is pivotally mounted in a vertical position to pivot about a pivot point corresponding to the node 37. The stem 61 projects downwardly and carries the transversely projecting arcuately shaped armature 11 on its lower extremity. Disposed on opposite sides of the upper extremity of the stem 61 are respective heating and cooling switches 65 and 67 in the form of electrical contacts which are connected with respective heating and cooling operators 75 and 77 by means of respective leads 79 and 81.

In operation, the leads 47 and 51 are connected with an AC or DC source and the thermostatic blade 39 is disposed in the environment of which the temperature is to be sensed. The respective heating and cooling operators 75 and 77 are then connected with heating and cooling sources, as for example respective dampers leading from a furnace and in air conditioning units.

When the thermostatic blade is cooled it will warp upwardly to the broken line position and collapse the resistor 17 thereby moving the coils 25 into closer spaced relationship while the expanding the resistor 19 to move the coils 27 into greater spaced relationship. Such contraction of the resistor 17 increases the rate of heat exchange relationship between the coils 25 thereby increasing the resistance of such resistor 17 and decreasing the rate of current flow from the node 31 and through such resistor 25, lead 35 and coil 13 to the node 37. Concurrently, the expansion of the resistor 19 decreases the rate of mutual heat exchange between the coils 27 thereby lowering the overall resistance of such resistor and decreasing the rate of current flow therethrough. Consequently, current flow from the node 31 through the resistor 27, lead 43 and coil to the node 37 is increased to increase, the electro-magnetic force produced by such coil while that for the coil 13 is decreased thereby causing the armature 1 1 to be attracted the left to rotate the switch operator 57 in a clockwise direction. Rotation of the switch operator 57 in a clockwise direction engages the upper extremity of the electrically conductive stem 61 with the contact 65 thereby completing a circuit from the lead 51, through node 37, contact 65 and lead 79 to the heating operator 75 to thereby initiate heating of the furnace (not shown).

l-leat from the furnace will heat the environment thereby heating the thermostatic blade 29 to its normal temperature thereby causing such blade to reassume its solid line position thereby expanding the resistor 17 and contracting the resistor 19 back to their nonnal unflexed position. Consequently, the rate of heat exchange between the coils 25 will be reduced while that for the coils 27 will be increased to thereby cause the resistors 17 and 19 to exhibit equal resistance. Consequently, current flow from the node 31 through the respective resistors 17 and 19 to the respective coils 13 and 15 will be equal thereby causing the switch operator 57 to assume its vertical position thereby opening the switch 65 and de-energizing the heating operator 75.

If the environment of which the temperature being sensed by the thermostatic blade 29 is cooled, the free end of such blade will flex downwardly to partially collapse the resistor 19 while expanding the resistor 17. Such collapse of the resistor .19 will move the coils 27 into closer spaced relationship while expansion of the resistor 17 moves the coils 25 into greater spaced relationship. Collapse of the resistor 19 increases the rate of the mutual heat exchange between the coils 27 and expansion of the resistor 17 decreases the rate of heat exchange between the coil 25. Such increase in the rate of heat exchange between the coils 27 increases the temperature and, consequently, the resistance of the resistor 19 thereby decreasing the rate of current flow from the node 31 through such resistor and lead 43 to the coil 15 thereby decreasing the electro-magnetic force produced by such coil. Correspondingly, the decrease in the rate of mutual heat exchange between the coils 25 of the resistor 17 decreases the temperature of such resistor thereby decreasing the resistance thereof and increasing the rate of current flow therethrough and through the lead 21 to the coil 13 thereby increasing the electro-magnetic force produced by such coil thereby causing the armature 11 to be moved to the right to rotate the switch operator 57 counterclockwise to engage the upper extremity of the stem 61 with the cooling switch contact 67. Engagement of the stem 61 with the cooling contact 67 provides current through the lead 81 to the cooling operator 77 thereby energizing such operator to initiate operation of an air conditioner (not shown). The air conditioner will then cool the environment thereby cooling the thermostatic blade 29 and causing it to return to its normal solid line position to again cause the resistors 17 and 19 to exhibit equal resistance to provide for equal current flow through the coils l3 and 15 thereby causing the operator 57 to assume its vertical position and allowing the cooling switch 67 to open.

From the foregoing it will be apparent that the armature control system of present invention provides a convenient means for controlling the positioning of an armature and consequently control of various operators in response to variations in a parameter in a thermostatic blade.

Various modifications and changes may be made with regard to the foregoing detailed description without departing from the spirit of the invention.

What is claimed is:

1. An annature control system comprising;

a movable armature;

coil meansdisposed adjacent said armature;

electrical resistance means having transverse portions disposed in heat exchange relationship and flexible for movement toward and away from one another to adjust said heat exchange relationship, the electrical resistance of said portions being temperature responsive so current flow therethrough is responsive to the temperature thereof; adjustment means for moving said portions toward and away from one another to adjust the proximity thereof and mutual heat transfer therebetween so the electrical current passing through said electrical resistance means is correspondingly adjusted; and circuit means connecting said resistance means with said coil means whereby said adjustment means may be adjusted to adjust the spacing between said transverse portions to alter the heat exchange relationship therebetween to adjust the resistance of said resistance means thereby adjusting the current flow to said coil means to adjust the electro-magnetic force on said armature to effect movement thereof. 2. An armature control system as set forth in claim 1 wherein;

said resistance means is in the form of a coiled lead with the coils thereof defining said transverse portions. 3. An armature control system as set forth in claim 1 wherein:

said adjustment means includes a thermostatic element responsive to temperature changes for adjusting the spacing of said portions. 4. An armature control system as set forth in claim 1 that includes;

mounting means urging said armature to a normal position;

and said coil means is arranged to urge said armature from its normal position when current flow therethrough is increased. 5. An armature control system as set forth in claim 1 wherein;

said circuit means includes a divided circuit formed with said resistance means defining a pair of legs thereof; and said adjustment means is coupled to the intermediate portion of said resistance means whereby adjustment of said resistance means in one direction increases the spacing between said transverse portions in one of said legs and decreases the spacing between said portion in the other of said legs. 6. An armature control system as set forth in claim 1 that includes;

mounting means for mounting said armature to urge it toward a normal position; and said coil means includes a first coil responsive to current increases therein to urge said armature in one direction from its normal position and a second coil responsive to current increases therein to urge said armature in a second direction from its normal position. 7. An armature control system as set forth in claim 1 that includes;

a movable electrical contact formed by said armature; a second electrical contact mounted in the path of said first contact; and an operator connected with said second. contact for being energized when said contacts are engaged with one another. 8. An armature control system as set forth in claim 1 that in cludes;

movable contact means formed by said armature; first and second spaced apart stationary contacts disposed in the path of said movable contact means; and first and second operators connected in circuit with said movable contact means and said respective first and second contact means for being energized when said movable contact means engages said respective first and second contact means.

includes;

operator means responsive to movement of said armature;

said adjustment means includes means for sensing a parameter and flexing means responsive to said parameter to flexing said resistance means and adjust the current to said coil means to move said armature and control said operator in response to said parameter. 

1. An armature control system comprising; a movable armature; coil means disposed adjacent said armature; electrical resistance means having transverse portions disposed in heat exchange relationship and flexible for movement toward and away from one another to adjust said heat exchange relationship, the electrical resistance of said portions being temperature responsive so current flow therethrough is responsive to the temperature thereof; adjustment means for moving said portions toward and away from one another to adjust the proximity thereof and mutual heat transfer therebetween so the electrical current passing through said electrical resistance means is correspondingly adjusted; and circuit means connecting said resistance means with said coil means whereby said adjustment means may be adjusted to adjust the spacing between said transverse portions to alter the heat exchange relationship therebetween to adjust the resistance of said resistance means thereby adjusting the current flow to said coil means to adjust the electro-magnetic force on said armature to effect movement thereof.
 2. An armature control system as set forth in claim 1 wherein; said resistance means is in the form of a coiled lead with the coils thereof defining said transverse portions.
 3. An armature control system as set forth in claim 1 wherein: said adjustment means includes a thermostatic element responsive to temperature changes for adjusting the spacing of said portions.
 4. An armature control system as set forth in claim 1 that includes; mounting means urging said armature to a normal position; and said coil means is arranged to urge said armature from its normal position when current flow therethrough is increased.
 5. An armature control system as set forth in claim 1 wherein; said circuit means includes a divided circuit formed with said resistance means defining a pair of legs thereof; and said adjustment means is coupled to the intermediate portion of said resistance means whereby adjustment of said resistance means in one direction increases the spacing between said transverse portions in one of said legs and decreases the spacing between said portion in the other of said legs.
 6. An armature control system as set forth in claim 1 that includes; mounting means for mounting said armature to urge it toward a normal position; and said coil means includes a first coil responsive to current increases therein to urge said armature in one direction from its normal position and a second coil responsive to current increases therein to urge said armature in a second direction from its normal position.
 7. An armature control system as set forth in claim 1 that includes; a movable electrical contact formed by said armature; a second electrical contact mounted in the path of said first contact; and an operator connected with said second contact for being energized when said contacts are engaged with one another.
 8. An armature control system as set forth in claim 1 that includes; movable contact means formed by said armature; first and second spaced apart stationary contacts disposed in the path of said movable contact means; and first and second operators connected in circuit with said movable contact means and said respective first and second contact means for being energized when said movable contact means engages said respective first and second contact means.
 9. An armature control system as set forth in claim 1 wherein; said circuit means includes a divided circuit formed with said resistance means in one leg thereof; and said adjustment means includes a thermostatic blade connected with said resistance means for flexure upon changes in temperature of said blade to adjust the spacing between said transverse portions.
 10. An armature control system as set forth in claim 1 that includes; operator means responsive to movement of said armature; said adjustment means includes means for sensing a parameter and flexing means responsive to said parameter to flexing said resistance means and adjust the current to said coil means to move said armature and control said operator in response to said parameter. 